Paging Mackey (IRS Ruling)
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Le Mans Master
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From: somers, ny
Paging Mackey (IRS Ruling)
Hi Mack.....happy new year.
Didn't you clarify the current IRS rule with NHRA HQ and the C4 is considered to have upper and lower control arms....meaning it is legal into the tens with 1/2 shaft loops????????
Didn't you clarify the current IRS rule with NHRA HQ and the C4 is considered to have upper and lower control arms....meaning it is legal into the tens with 1/2 shaft loops????????
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From: Former NCM Drag Racing coordinator, National director Corvette Challenge Spring Hill, Tennessee: Whiting, New Jersey
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Originally Posted by ralph
Hi Mack.....happy new year.
Didn't you clarify the current IRS rule with NHRA HQ and the C4 is considered to have upper and lower control arms....meaning it is legal into the tens with 1/2 shaft loops????????
Didn't you clarify the current IRS rule with NHRA HQ and the C4 is considered to have upper and lower control arms....meaning it is legal into the tens with 1/2 shaft loops????????
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From: Former NCM Drag Racing coordinator, National director Corvette Challenge Spring Hill, Tennessee: Whiting, New Jersey
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Originally Posted by ralph
thanks Mack........how long ago was that?
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From: The Top of Utah
Originally Posted by mackeyred96
Ralph, last I talked to NHRA TECH HQ the C4 IRS was good to 10.00 but at 10.99 you do need 1/2 shaft loops.
RACE ON!!!
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From: The Top of Utah
Originally Posted by Major Spray
Yes any IRS setup is legal to 10.00 as long as you have upper and lower control arms.
"Cars with independent rear suspension using upper and lower (both) control arms may retain swing axle assembly regardless of weight and e.t."
This is the same rule since the IRS rules came into being.
RACE ON!!!
Thread Starter
Le Mans Master
Joined: Feb 1999
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From: somers, ny
thanks all for the quick replies. I was having a debate on another forum and wanted to make sure i had my facts straight.
Jim, i'm pretty sure the rule DID change in the last 4-5 years. There was an absolute 11.00 limit on the IRS. Then they added the exception for the upper/lower control arms. i THOUGHT there was still a 10.00 limit, but i could be wrong. Jesse posted a picture of the Toms setup and the title said something about legal to 7.50. Although Mackey mentioned it here, so maybe i'm not completely senile.....or maybe we both are
Jim, i'm pretty sure the rule DID change in the last 4-5 years. There was an absolute 11.00 limit on the IRS. Then they added the exception for the upper/lower control arms. i THOUGHT there was still a 10.00 limit, but i could be wrong. Jesse posted a picture of the Toms setup and the title said something about legal to 7.50. Although Mackey mentioned it here, so maybe i'm not completely senile.....or maybe we both are
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From: Lithia FL
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Originally Posted by Major Spray
Yes any IRS setup is legal to 10.00 as long as you have upper and lower control arms. Tom's Differental is now selling a kit that adds links to make the C2 and C3 setups legal as well 
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From: The Top of Utah
Originally Posted by CFI-EFI
Where does the 10.00 keep coming from? To quote the, NHRA 2005 Rulebook:
"Cars with independent rear suspension using upper and lower (both) control arms may retain swing axle assembly regardless of weight and e.t."
This is the same rule since the IRS rules came into being.
RACE ON!!!
"Cars with independent rear suspension using upper and lower (both) control arms may retain swing axle assembly regardless of weight and e.t."
This is the same rule since the IRS rules came into being.
RACE ON!!!
RACE ON!!!
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From: Former NCM Drag Racing coordinator, National director Corvette Challenge Spring Hill, Tennessee: Whiting, New Jersey
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OK, IT'S NOT 10.00.
I must have made it up, I'm sorry.
Ralph, there is no limit on IRS,
I must have made it up, I'm sorry.
Ralph, there is no limit on IRS,
Drifting
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From: Fort Salonga NY
You are correct I don't see any limit on ET mentioned I am sure you would be good till 7.50 but the chassis requirments may be a problem when you get below that not that we have to worry about going faster then 7.50 my error. 
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From: Former NCM Drag Racing coordinator, National director Corvette Challenge Spring Hill, Tennessee: Whiting, New Jersey
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Originally Posted by Red96Coupe
Hmmmmm 